powerpc/mm: Drop WIMG in favour of new constants

PowerISA 3.0 introduces two pte bits with the below meaning for radix:
  00 -> Normal Memory
  01 -> Strong Access Order (SAO)
  10 -> Non idempotent I/O (Cache inhibited and guarded)
  11 -> Tolerant I/O (Cache inhibited)

We drop the existing WIMG bits in the Linux page table in favour of the
above constants. We loose _PAGE_WRITETHRU with this conversion. We only
use writethru via pgprot_cached_wthru() which is used by
fbdev/controlfb.c which is Apple control display and also PPC32.

With respect to _PAGE_COHERENCE, we have been marking hpte always
coherent for some time now. htab_convert_pte_flags() always added
HPTE_R_M.

NOTE: KVM changes need closer review.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

2 files changed, 11 insertions, 12 deletions

diff --git a/arch/powerpc/kvm/book3s_64_mmu_hv.c b/arch/powerpc/kvm/book3s_64_mmu_hv.c
index c7b78d8336b2..05f09ae82587 100644
--- a/arch/powerpc/kvm/book3s_64_mmu_hv.c
+++ b/arch/powerpc/kvm/book3s_64_mmu_hv.c
@@ -447,7 +447,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 	struct revmap_entry *rev;
 	struct page *page, *pages[1];
 	long index, ret, npages;
-	unsigned long is_io;
+	bool is_ci;
 	unsigned int writing, write_ok;
 	struct vm_area_struct *vma;
 	unsigned long rcbits;
@@ -503,7 +503,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 	smp_rmb();
 
 	ret = -EFAULT;
-	is_io = 0;
+	is_ci = false;
 	pfn = 0;
 	page = NULL;
 	pte_size = PAGE_SIZE;
@@ -521,7 +521,7 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 			pfn = vma->vm_pgoff +
 				((hva - vma->vm_start) >> PAGE_SHIFT);
 			pte_size = psize;
-			is_io = hpte_cache_bits(pgprot_val(vma->vm_page_prot));
+			is_ci = pte_ci(__pte((pgprot_val(vma->vm_page_prot))));
 			write_ok = vma->vm_flags & VM_WRITE;
 		}
 		up_read(&current->mm->mmap_sem);
@@ -558,10 +558,9 @@ int kvmppc_book3s_hv_page_fault(struct kvm_run *run, struct kvm_vcpu *vcpu,
 		goto out_put;
 
 	/* Check WIMG vs. the actual page we're accessing */
-	if (!hpte_cache_flags_ok(r, is_io)) {
-		if (is_io)
+	if (!hpte_cache_flags_ok(r, is_ci)) {
+		if (is_ci)
 			goto out_put;
-
 		/*
 		 * Allow guest to map emulated device memory as
 		 * uncacheable, but actually make it cacheable.
diff --git a/arch/powerpc/kvm/book3s_hv_rm_mmu.c b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
index 4cb8db05f3e5..99b4e9d5dd23 100644
--- a/arch/powerpc/kvm/book3s_hv_rm_mmu.c
+++ b/arch/powerpc/kvm/book3s_hv_rm_mmu.c
@@ -175,7 +175,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
 	unsigned long g_ptel;
 	struct kvm_memory_slot *memslot;
 	unsigned hpage_shift;
-	unsigned long is_io;
+	bool is_ci;
 	unsigned long *rmap;
 	pte_t *ptep;
 	unsigned int writing;
@@ -199,7 +199,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
 	gfn = gpa >> PAGE_SHIFT;
 	memslot = __gfn_to_memslot(kvm_memslots_raw(kvm), gfn);
 	pa = 0;
-	is_io = ~0ul;
+	is_ci = false;
 	rmap = NULL;
 	if (!(memslot && !(memslot->flags & KVM_MEMSLOT_INVALID))) {
 		/* Emulated MMIO - mark this with key=31 */
@@ -250,7 +250,7 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
 			if (writing && !pte_write(pte))
 				/* make the actual HPTE be read-only */
 				ptel = hpte_make_readonly(ptel);
-			is_io = hpte_cache_bits(pte_val(pte));
+			is_ci = pte_ci(pte);
 			pa = pte_pfn(pte) << PAGE_SHIFT;
 			pa |= hva & (host_pte_size - 1);
 			pa |= gpa & ~PAGE_MASK;
@@ -267,9 +267,9 @@ long kvmppc_do_h_enter(struct kvm *kvm, unsigned long flags,
 	else
 		pteh |= HPTE_V_ABSENT;
 
-	/* Check WIMG */
-	if (is_io != ~0ul && !hpte_cache_flags_ok(ptel, is_io)) {
-		if (is_io)
+	/*If we had host pte mapping then  Check WIMG */
+	if (ptep && !hpte_cache_flags_ok(ptel, is_ci)) {
+		if (is_ci)
 			return H_PARAMETER;
 		/*
 		 * Allow guest to map emulated device memory as